Screw-driver



TiniTEn STATES PATENT ()EFICE.

JOSEPH R. DOOLITTLE, CF SOUTHINGTON, CONNECTICUT.

SCREW=DRIVER.

SPECIFICATION forming part of Letters Patent No. 339,277, dated April 6, 1886.

Application filed December 18, 1885. Serial No. 186,059. (No model.)

To all whom it may concern: near the outer edges, force the pawls into the Be it known that I, JOSEPH R. DOOLITTLE, grooves a. a citizen of the United States, residing at The shank A, Fig.1,is made of a round rod Southington, in the county of Hartford and of steel, and the lower end is flattened. The State of Connecticut, have invented certain shank moves through the ferrule B, and has new and useful Improvements in Screw-Drivtwo rectangular spiral grooves, a, Fig. 4, in it, ers, of which the following is a specification, into which the teeth of the pawls move to roreference being had therein to theaccompanytatc the blade. It hasacollar at each end of the ing drawings, in whichgrooves, the lower collar being marked D and 55 Figure 1 is an elevation of my improved the latter E, to limit the sliding movement of screw-driver with the handle in section, and the shank. When the pawls are at the lower shows the pawls in position. Fig. 2 is an en end of the grooves, the lower collar prevents larged view of the side of the pawls, and Fig. them from sliding over the blade, and the tool 3 is a view of the inner edge of one of the may then be used asthe ordinary screw-driver. 6 pawls. Fig. 4 is a cross-section of the shank. Constructed and arranged as above described, Fig. 5 is a crosssection of one of the pawls on the operation of the screw-driver is as follows: line 00, Fig. 2. \Vhen the handle is pushed down, the teeth of The object of my improvement in rotary the pawls engage with and rotate the blade, screw-drivers is a construction whereby the and when the handle is raised the pawls trip 65 blade and handle may be separated without over the grooves without moving the blade.

rotating either part. Having described my improved screw- To this end the invention consists in making driver and its mode of operating, what I claim the shank with aspiral groove, and in attachas new, and desire to secure by Letters Patent, ing to, the handle one or more pawls, as is is 7o hereinafter more fully described and ex- 1. The ferrule 13, slotted atits forward end, plained. in combination with a pawl, C, pivoted in this To enable others to make my improved slot, the spirallygrooved shank A, engaging screw-driver,I willgive adetailed description with said pawl, and spring 6, set into a reof the same. cess of said ferrule and pressing against said 7 5 0 The wood portion of the handle is in the pawl at the rear end thereof, substantially as usual form, and the ferrule B, fitting onto it, set forth. is elongated and perforated, and into the pcr- 2. The ferrule B, slotted at its forward end, foration the shank of the blade fits and freely in combination with a pawl, C, pivoted in this moves. In its end a slot is made, into which slot, the spirally-grooved shank A, having a 80 5 the pawls C lit, and also holes into which the collar at the end of the groove, the groove of spiral springs c are inserted for operating the the former engaging with said pawl, and a pawls. The pawlsC fit in the slot in the hanspring, 0, set into a recess of said ferrule and die, and are beveled on their upper ends. operating against the rear end of said pawl, Their lower ends are rounded to the form of substantially as set forth. 8 5 40 the end of the ferrule, and on the inner sides In testimony whereof I affix mysignaturein are lugs or teeth, a, formed to fit into the presence of two witnesses. grooves in the shank. The teeth t are flat on 1 their under surfaces, 72, Fig. 5, and beveled on JOSEPH DOOLIT'I the upper faces, 9, and fit in the grooves a in XVitnesses: the shank. The pawls are pivoted near the GEORGE TERRY,

top and inner side, and the springs c, acting J. EDWARD LUDINGTON. 

